U.S. patent application number 15/778661 was filed with the patent office on 2018-12-06 for transport system and transport method.
The applicant listed for this patent is MURATA MACHINERY, LTD.. Invention is credited to Kazumi HARASAKI.
Application Number | 20180348778 15/778661 |
Document ID | / |
Family ID | 59014018 |
Filed Date | 2018-12-06 |
United States Patent
Application |
20180348778 |
Kind Code |
A1 |
HARASAKI; Kazumi |
December 6, 2018 |
TRANSPORT SYSTEM AND TRANSPORT METHOD
Abstract
A track in a transport system includes a standby section
associated with a certain processing apparatus to allow a transport
vehicle to wait. When determining a transport request to transport
a FOUP to a load port of the certain processing apparatus exists,
the controller allocates, to the transport vehicle, a first
transport command to transport the FOUP to the standby section.
When reaching the standby section, the transport vehicle waits
while holding the FOUP. Subsequently, when determining that the
FOUP is transportable to the load port of the certain processing
apparatus, the controller allocates, to the transport vehicle, a
second transport command to transport the FOUP to the load port of
the certain processing apparatus.
Inventors: |
HARASAKI; Kazumi;
(Inuyama-shi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
MURATA MACHINERY, LTD. |
Kyoto-shi, Kyoto |
|
JP |
|
|
Family ID: |
59014018 |
Appl. No.: |
15/778661 |
Filed: |
October 19, 2016 |
PCT Filed: |
October 19, 2016 |
PCT NO: |
PCT/JP2016/080976 |
371 Date: |
May 24, 2018 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H01L 21/67769 20130101;
G05D 1/0225 20130101; H01L 21/67276 20130101; G05D 2201/0213
20130101; G05D 2201/0216 20130101; H01L 21/67727 20130101; H01L
21/67742 20130101; H01L 21/67745 20130101 |
International
Class: |
G05D 1/02 20060101
G05D001/02; H01L 21/677 20060101 H01L021/677 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 9, 2015 |
JP |
2015-240044 |
Claims
1-8. (canceled)
9. A transport system comprising: a track; a plurality of transport
vehicles to travel along the track and transport an object to a
load port of each of a plurality of processing apparatuses; and a
controller configured or programmed to communicate with and control
operation of each of the plurality of transport vehicles; wherein
the track is provided with a standby section associated with a
certain processing apparatus of the plurality of processing
apparatuses to allow a certain transport vehicle of the plurality
of transport vehicles to wait; when the controller determines that
there exists a transport request to transport the object to a load
port of the certain processing apparatus, the controller allocates,
to the certain transport vehicle, a first transport command to
transport the object to the standby section; when reaching the
standby section, the certain transport vehicle to which the first
transport command has been allocated waits in the standby section
while holding the object; and when the controller determines that
the object is transportable to the load port of the certain
processing apparatus, after allocating the first transport command
to the certain transport vehicle, the controller allocates, to the
certain transport vehicle to which the first transport command has
been allocated, a second transport command to transport the object
to the load port of the certain processing apparatus.
10. The transport system according to claim 9, wherein the certain
transport vehicle travels along the track in one direction; and the
standby section is connected in parallel with a second travel
section continuous with an upstream side of a first travel section
including a position to transfer the object to the load port of the
certain processing apparatus.
11. The transport system according to claim 10, wherein the first
travel section is provided for a plurality of the certain
processing apparatuses.
12. The transport system according to 9, wherein when the
controller determines that a standby section-withdrawal condition
is satisfied, the controller allocates, to the certain transport
vehicle to which the first transport command has been allocated, a
third transport command to transport the object to a predetermined
destination.
13. The transport system according to claim 12, wherein when the
controller determines, as the standby section-withdrawal condition,
that at least a predetermined time has elapsed since the certain
transport vehicle to which the first transport command has been
allocated reaches the standby section, the controller allocates the
third transport command to the certain transport vehicle to which
the first transport command has been allocated.
14. The transport system according to claim 12, wherein when the
controller determines, as the standby section-withdrawal condition,
that at least a predetermined number of the transport vehicles are
waiting in the standby section, the controller allocates the third
transport command to at least one of the transport vehicles waiting
in the standby section.
15. The transport system according to claim 12, wherein the certain
transport vehicle travels along the track in one direction; when at
least two of the plurality of the transport vehicles are waiting in
the standby section, and a transport command to withdraw from the
standby section is allocated to a specific one of the at least two
of the plurality of transport vehicles waiting in the standby
section, excluding a most downstream transport vehicle, the
controller allocates a transport command to withdraw from the
standby section and transport the object to the standby section
again, to another transport vehicle downstream from the specific
one of the transport vehicles; and when the controller determines,
as the standby section-withdrawal condition, that the certain
transport vehicle to which the first transport command has been
allocated has withdrawn from the standby section at least a
predetermined number of times, the controller allocates the third
transport command to the certain transport vehicle to which the
first transport command has been allocated.
16. A transport method performed in a transport system including a
track, a plurality of transport vehicles to travel along the track
and transport an object to a load port of each of a plurality of
processing apparatuses, and a controller configured or programmed
to communicate with each of the plurality of transport vehicles and
control operation of each of the plurality of transport vehicles,
the track being provided with a standby section associated with a
certain processing apparatus of the plurality of processing
apparatuses to allow a certain transport vehicle of the plurality
of transport vehicles to wait, the transport method comprising: the
controller allocating to the certain transport vehicle a first
transport command to transport the object to the standby section
when determining that there exists a transport request to transport
the object to a load port of the certain processing apparatus; the
certain transport vehicle to which the first transport command has
been allocated waiting in the standby section while holding the
object when reaching the standby section; and the controller
allocating to the certain transport vehicle to which the first
transport command has been allocated a second transport command to
transport the object to the load port of the certain processing
apparatus, when determining that the object is transportable to the
load port of the certain processing apparatus, after allocating the
first transport command to the certain transport vehicle.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
[0001] The present disclosure relates to a transport system and a
transport method.
2. Description of the Related Art
[0002] A known example of a transport system applied to a
semiconductor fabrication plant includes a track, a plurality of
transport vehicles traveling along the track to transport an object
to load ports of a plurality of processing apparatuses, and a
controller communicating with each of the transport vehicles and
controlling the operation of each of the transport vehicles (for
example, see Japanese Unexamined Patent Publication No.
2000-339027).
[0003] In the transport system as described above, when there
exists a transport request to transport an object to a load port in
a situation where an object is not transportable to the load port,
the controller allocates, to a transport vehicle, a transport
command to transport the object to a storage shelf or the like for
temporarily storing an object. Subsequently, when the situation
changes so that an object is transportable to the load port, the
controller allocates, to one of the transport vehicles, a transport
command to transport the object to the load port from the storage
shelf or the like.
[0004] Specifically, when an object temporarily stored in a storage
shelf or the like is to be transported from the storage shelf or
the like to the load port, the controller detects a transport
vehicle that can transport the object and allocates, to the
detected transport vehicle, a transport command to transport the
object from the storage shelf or the like to the load port. The
transport vehicle to which the transport command is allocated picks
up the object temporarily stored in the storage shelf or the like,
transports the object to the load port, and unloads the object.
This operation takes time. There is, therefore, a limit in reducing
the time taken to unload the object to a load port after the
situation changes so that the object is transportable to the load
port.
[0005] In particular, when the distance between the storage shelf
or the like and the load port is long, the time required for the
transport vehicle to pick up the object temporarily stored in the
storage shelf or the like, transport the object to the load port,
and unload the object is long. As a result, for example, the
operating rate may be reduced in a certain processing apparatus,
such as a processing apparatus with high processing speed.
SUMMARY OF THE INVENTION
[0006] Preferred embodiments of the present invention provide
transport systems and transport methods, in which a reduction in an
operating rate of a processing apparatus is decreased or
prevented.
[0007] A transport system according to a preferred embodiment of
the present invention includes a track, a plurality of transport
vehicles to travel along the track and transport an object to a
load port of each of a plurality of processing apparatuses, and a
controller configured or programmed to communicate with each of the
transport vehicles and control operation of each of the transport
vehicles. The track is provided with a standby section associated
with a certain one of the plurality of processing apparatuses to
allow the transport vehicle to wait. When the controller determines
that there exists a transport request to transport the object to a
load port of the certain one of the plurality of processing
apparatuses, the controller allocates, to the transport vehicle, a
first transport command to transport the object to the standby
section. When reaching the standby section, the transport vehicle
to which the first transport command has been allocated waits in
the standby section while holding the object. When the controller
determines that the object is transportable to the load port of the
certain processing apparatus, after allocating the first transport
command to the transport vehicle, the controller allocates, to the
transport vehicle to which the first transport command has been
allocated, a second transport command to transport the object to
the load port of the certain processing apparatus.
[0008] In this transport system, even if the object is not
transportable to the load port of the certain processing apparatus,
the transport vehicle picks up the object and starts travelling
toward the standby section associated with the certain processing
apparatus. When the situation changes so that the object is
transportable to the load port of the certain processing apparatus,
the transport vehicle travelling toward the standby section or the
transport vehicle reaching the standby section and waiting while
holding the object is able to immediately transport the object to
the load port of the certain processing apparatus without the need
for performing an operation, such as picking-up, again. This
configuration decreases or prevents a reduction in an operating
rate of the certain processing apparatus.
[0009] In a transport system according to a preferred embodiment of
the present invention, the transport vehicle may travel along the
track in one direction, and the standby section may be connected in
parallel with a second travel section continuous to an upstream
side of a first travel section including a position to transfer the
object to the load port of the certain processing apparatus. This
configuration enables the transport vehicle to wait in the standby
section without interrupting travel of the transport vehicle from
the second travel section to the first travel section.
[0010] In a transport system according to a preferred embodiment of
the present invention, the first travel section may be provided for
a plurality of the certain processing apparatuses. In this
configuration, since one standby section is associated with a
plurality of certain processing apparatuses, the area of the space
necessary to provide the standby section is able to be reduced.
[0011] In a transport system according to a preferred embodiment of
the present invention, when the controller determines that a
standby section-withdrawal condition is satisfied, the controller
may allocate, to the transport vehicle to which the first transport
command has been allocated, a third transport command to transport
the object to a predetermined destination. For example, this
configuration is able to prevent the transport vehicle from staying
in the standby section due to some error occurring in the certain
processing apparatus.
[0012] In a transport system according to a preferred embodiment of
the present invention, when the controller determines, as the
standby section-withdrawal condition, that a predetermined time or
longer has elapsed since the transport vehicle to which the first
transport command has been allocated reaches the standby section,
the controller may allocate the third transport command to the
transport vehicle to which the first transport command has been
allocated. For example, this configuration is able to prevent the
transport vehicle from staying in the standby section due to some
error occurring in the certain processing apparatus.
[0013] In a transport system according to a preferred embodiment of
the present invention, when the controller determines, as the
standby section-withdrawal condition, that at least a predetermined
number of the transport vehicles are waiting in the standby
section, the controller may allocate the third transport command to
at least one of the transport vehicles waiting in the standby
section. For example, this configuration is able to prevent the
transport vehicle from staying in the standby section due to some
error occurring in the certain processing apparatus.
[0014] In a transport system according to a preferred embodiment of
the present invention, the transport vehicle may travel along the
track in one direction. When a plurality of the transport vehicles
are waiting in the standby section, and a transport command to
withdraw from the standby section is allocated to one of the
transport vehicles waiting in the standby section, excluding the
transport vehicle most downstream, the controller may allocate a
transport command to withdraw from the standby section and
transport the object to the standby section again, to another
transport vehicle downstream from the one of the transport
vehicles. When the controller determines, as the standby
section-withdrawal condition, that the transport vehicle to which
the first transport command has been allocated has withdrawn from
the standby section at least a predetermined number of times, the
controller may allocate the third transport command to the
transport vehicle to which the first transport command has been
allocated. For example, this configuration is able to prevent
ejection control (control of allowing the downstream transport
vehicle to withdraw from the standby section and return to the
standby section again in order to withdraw the upstream transport
vehicle from the standby section) from being repeated due to some
trouble occurring in the certain processing apparatus.
[0015] A transport method according to a preferred embodiment of
the present invention is performed in a transport system. The
transport system includes a track, a plurality of transport
vehicles to travel along the track and transport an object to a
load port of each of a plurality of processing apparatuses, and a
controller configured or programmed to communicate with each of the
transport vehicles and control operation of each of the transport
vehicles. The track is provided with a standby section associated
with a certain one of the plurality of processing apparatuses to
allow the transport vehicle to wait. The transport method includes
a first step, performed by the controller, of allocating, to the
transport vehicle, a first transport command to transport the
object to the standby section, when determining that there exists a
transport request to transport the object to a load port of the
certain processing apparatus; a second step, performed by the
transport vehicle to which the first transport command has been
allocated, of waiting in the standby section while holding the
object, when reaching the standby section; and a third step,
performed by the controller, of allocating, to the transport
vehicle to which the first transport command has been allocated, a
second transport command to transport the object to the load port
of the certain processing apparatus, when determining that the
object is transportable to the load port of the certain processing
apparatus, after allocating the first transport command to the
transport vehicle.
[0016] This transport method decreases or prevents reduction in an
operating rate of the certain processing apparatus, as in the
transport system described above.
[0017] Preferred embodiments of the present invention decrease or
prevent reduction in an operating rate of a certain processing
apparatus.
[0018] The above and other elements, features, steps,
characteristics and advantages of the present invention will become
more apparent from the following detailed description of the
preferred embodiments with reference to the attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] FIG. 1 is a partial plan view of a transport system
according to a preferred embodiment of the present invention.
[0020] FIG. 2 is a plan view for explaining standby control in the
transport system in FIG. 1.
[0021] FIG. 3 is a plan view for explaining standby control in the
transport system in FIG. 1.
[0022] FIG. 4 is a plan view for explaining standby control in the
transport system in FIG. 1.
[0023] FIG. 5 is a plan view for explaining first withdrawal
control in the transport system in FIG. 1.
[0024] FIG. 6 is a plan view for explaining first withdrawal
control in the transport system in FIG. 1.
[0025] FIG. 7 is a plan view for explaining second withdrawal
control in the transport system in FIG. 1.
[0026] FIG. 8 is a plan view for explaining third withdrawal
control in the transport system in FIG. 1.
[0027] FIG. 9 is a plan view for explaining third withdrawal
control in the transport system in FIG. 1.
[0028] FIG. 10 is a partial plan view of the transport system
according to a modification of a preferred embodiment of the
present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0029] Preferred embodiments of the present invention will be
described in detail below with reference to the figures. The same
or corresponding parts in the figures are denoted by the same
reference signs, and an overlapping description will be
omitted.
[0030] As illustrated in FIG. 1, a transport system 1 includes a
track 10, a plurality of transport vehicles 20, and a controller
50. The track 10 is preferably provided in the vicinity of a
ceiling of a semiconductor fabrication plant equipped with a
plurality of processing apparatuses 100. The transport vehicle 20
is an overhead hoist transfer (OHT) and travels on the track 10 in
one direction while being suspended from the track 10. The
transport vehicle 20 transports a front opening unified pod (FOUP)
90 accommodating a plurality of semiconductor wafers as an object
to a load port 101 of each processing apparatus 100. The controller
50 communicates with each transport vehicle 20 and controls the
operation of each transport vehicle 20.
[0031] The track 10 includes a plurality of sections 10a, 10b, 10c,
10d, and 10e. The section 10b is linearly connected to the
downstream side of the section 10a. The section 10c is curved to be
bent back and connected to the downstream side of the section 10b.
The section 10d is linearly connected to the downstream side of the
section 10c. The section 10e branches from the connection position
between the section 10c and the section 10d and merges with the
connection position between the section 10a and the section
10b.
[0032] In such a track 10, the transport vehicle 20 entering
through the upstream side of the section 10a travels from the
section 10a to the section 10b, then travels to the section 10c,
thereafter travels to the section 10d, and exits to the downstream
side. Alternatively, the transport vehicle 20 entering through the
upstream side of the section 10a travels from the section 10a to
the section 10b, then travels to the section 10c, thereafter
travels from the section 10c to the section 10e, and travels to the
section 10b again. The configuration of the track 10 is illustrated
only by way of example and not limitative.
[0033] The section 10b is provided with a standby section 30
associated with certain processing apparatuses 100A, 100B, and
100C, of a plurality of processing apparatuses 100, to allow the
transport vehicle 20 to wait. In the standby section 30, a
plurality of standby points 31 and 32 are set, which are positions
where the transport vehicle 20 waits. In the figure, a standby
point 31 set on the most upstream side of the standby section 30
and four standby points 32a, 32b, 32c, and 32d set on the
downstream side of the standby point 31 are illustrated as standby
points.
[0034] In the section 10c, a position is set to transfer a FOUP to
the load port 101 of each of the certain processing apparatuses
100A, 100B, and 100C. Three certain processing apparatuses 100A,
100B, and 100C are disposed along the section 10c in this order
from the upstream side, and the load ports 101 of certain
processing apparatuses 100A, 100B, and 100C are positioned below
the section 10c. When a FOUP 90 is placed onto the load port 101,
each of the certain processing apparatuses 100A, 100B, and 100C
takes in a semiconductor wafer in the FOUP and performs a
predetermined process on the semiconductor wafer. Each of the
certain processing apparatuses 100A, 100B, and 100C returns the
semiconductor wafer subjected to a predetermined process into the
FOUP 90 and sets the FOUP 90 to a state transportable by the
transport vehicle 20.
[0035] The certain processing apparatuses 100A, 100B, and 100C are
devices that perform a process with higher processing speed, among
the processing apparatuses 100 (that is, among the processing
apparatuses 100, a process that requires a shorter time to perform
a predetermined process on a semiconductor wafer and set the FOUP
90 to a state transportable by the transport vehicle 20, after the
FOUP 90 is placed on the load port 101). Examples of the certain
processing apparatuses 100A, 100B, and 100C include testing devices
and lithography devices.
[0036] In the section 10c, normal processing apparatuses 100D and
100E are disposed, which are processing apparatuses 100 other than
the certain processing apparatuses 100A, 100B, and 100C. The normal
processing apparatuses 100D and 100E are disposed along the section
10c in this order from the upstream side, and the load ports 101 of
the normal processing apparatuses 100D and 100E are positioned
below the section 10c. When a FOUP 90 is placed on the load port
101, each of the normal processing apparatuses 100D and 100E takes
in a semiconductor wafer in the FOUP and performs a predetermined
process on the semiconductor wafer. Each of the certain processing
apparatuses 100A, 100B, and 100C returns the processed
semiconductor wafer into the FOUP 90 and sets the FOUP 90 to a
state transportable by the transport vehicle 20. The normal
processing apparatuses 100D and 100E perform a process with lower
processing speed than the certain processing apparatuses 100A,
100B, and 100C.
[0037] A stocker 40 is disposed in the vicinity of the connection
position between the section 10c and the section 10d. The stocker
40 is a facility that temporarily stores a plurality of FOUPs 90
transported by the transport vehicles 20. The stocker includes a
port 41 positioned below the connection position between the
section 10c and the section 10d. When a FOUP 90 is placed onto the
port 41, the stocker 40 takes in the FOUP 90 and temporarily stores
the FOUP 90. When the temporarily stored FOUP 90 is to be obtained
by the transport vehicle 20, the FOUP 90 is placed onto the port 41
and set to a state transportable by the transport vehicle 20. For
example, a storage shelf to temporarily store an object may be used
instead of the stocker 40.
[0038] The transport vehicle 20 includes a transfer mechanism to
transfer a FOUP 90 to the load port 101. The transfer mechanism
includes, for example, a grip to grip a FOUP 90 and an elevator
mechanism to elevate and lower the grip. In this configuration, for
example, the transport vehicle 20 stops at a position to transfer
the FOUP 90 to the load port 101 of the certain processing
apparatus 100A, and, in this state, the transfer mechanism operates
to transfer the FOUP 90 to the load port 101. The transfer of the
FOUP 90 to the load port 101 includes a case where the FOUP 90 held
by (loaded on) the transport vehicle 20 is supplied (unloaded) to
the load port 101 and a case where the transport vehicle 20 obtains
(picks up) the FOUP 90 placed on the load port 101.
[0039] The controller 50 is preferably configured or programmed to
include a transport controller 50A and a transport vehicle
controller 50B. The transport controller 50A is a higher-level
controller for the transport vehicle controller 50B. The transport
controller 50A communicates with the transport vehicle controller
50B and a fabrication controller (not illustrated). The fabrication
controller communicates with each processing apparatus 100 and
submits to the transport controller 50A a transport request to
transport a FOUP 90 to the load port 101 of each processing
apparatus 100. When the transport controller 50A determines that a
transport request exists, the transport vehicle controller 50B
allocates a transport command corresponding to the transport
request to one of the transport vehicles 20. The transport
controller 50A, the transport vehicle controller 50B, and the
fabrication controller preferably are each, for example, a computer
device including a processor, a memory, a storage, and a
communication device. In each controller, the processor executes
predetermined software (program) read into a memory or the like and
controls read and write of data in the memory and the storage and
communication between the controllers through the communication
device to implement the functions of the controller as described
later.
[0040] In the transport system 1, standby control described below
is performed. The standby control performed in the following
situation will be described by way of example. As illustrated in
FIG. 1, a FOUP 90 is placed on the load port 101 of the certain
processing apparatus 100A, of three certain processing apparatuses
100A, 100B, and 100C disposed along the section 10c. Therefore, at
this time, the certain processing apparatus 100A is not in a
situation where the FOUP 90 is transportable to its load port 101.
In order to obtain the FOUP 90 placed on the load port 101 of the
certain processing apparatus 100A, the transport vehicle 20A is
traveling through the section 10c toward the certain processing
apparatus 100A.
[0041] In such a situation, when there exists a transport request
to transport another FOUP 90 to the load port 101 of the certain
processing apparatus 100A, the transport controller 50A
communicates with the fabrication controller to determine that the
transport request exists. Here, the transport controller 50A
creates a first transport command to transport a FOUP 90 to the
standby section 30. The transport controller 50A then transmits the
first transport command to the transport vehicle controller 50B.
The transport vehicle controller 50B receiving the first transport
command allocates the first transport command to the transport
vehicle 20B (first step). Specifically, the first transport command
is a command that allows the transport vehicle 20B to transport a
FOUP 90 to the standby point 31 in the standby section 30. The
figure illustrates a state in which the transport vehicle 20B that
has been allocated with the first transport command is travelling
through the section 10a while holding a FOUP 90 to be transferred
to the load port 101 of the certain processing apparatus 100A. Even
when a FOUP 90 is not placed on the load port 101 of the certain
processing apparatus 100A and the certain processing apparatus 100A
is in a situation where a FOUP 90 is transportable to its load port
101, the transport vehicle controller 50B allocates, to the
transport vehicle 20B, the first transport command to transport a
FOUP 90 to the standby section 30.
[0042] Subsequently, as illustrated in FIG. 2, the transport
vehicle 20B reaches the standby point 31, and the first transport
command is completed. The transport vehicle 20B reaching the
standby point 31 waits at the standby point 31 while holding the
FOUP 90 (second step).
[0043] Subsequently, as illustrated in FIG. 3, when the standby
point 32 downstream from the transport vehicle 20B is vacant (that
is, another transport vehicle 20 is not waiting) in the standby
section 30, the transport vehicle controller 50B allocates, to the
transport vehicle 20B, a move command to move to the standby point
32 on the downstream side. The figure illustrates a state in which
the transport vehicle 20B, to which the move command to move to the
standby point 32a has been allocated by the transport vehicle
controller 50B, has been moved to the standby point 32a. The
transport vehicle 20B reaching the standby point 32a waits at the
standby point 32a while holding the FOUP 90.
[0044] In the figure, the transport vehicle 20A has reached a
position to transfer a FOUP 90 to the load port 101 of the certain
processing apparatus 100A. The transport vehicle 20A obtains the
FOUP 90 placed on the load port 101 of the certain processing
apparatus 100A. The certain processing apparatus 100A thus enters a
state in which the FOUP 90 is transportable to its load port
101.
[0045] Subsequently, as illustrated in FIG. 4, the transport
controller 50A communicates with the fabrication controller to
determine that a FOUP 90 is transportable to the load port 101 of
the certain processing apparatus 100A. Here, the transport
controller 50A creates a second transport command to transport a
FOUP 90 to the load port 101 of the certain processing apparatus
100A. The transport controller 50A then transmits the second
transport command to the transport vehicle controller 50B. The
transport vehicle controller 50B receiving the second transport
command allocates the second transport command to the transport
vehicle 20B to which the first transport command has been allocated
(third step). Subsequently, the transport vehicle 20B transports
the FOUP 90 from the standby point 32a to the load port 101 of the
certain processing apparatus 100A, and the second transport command
is completed.
[0046] At this time, the transport vehicle controller 50B allows
the transport vehicle 20A obtaining the FOUP 90 from the load port
101 of the certain processing apparatus 100A to travel from the
position to transfer a FOUP 90 to the load port 101 to another
position on the track 10.
[0047] In the transport system 1, first withdrawal control, second
withdrawal control, and third withdrawal control described below
preferably are performed.
[0048] First of all, the first withdrawal control performed in the
following situation will be described by way of example. As
illustrated in FIG. 5, a FOUP 90 is placed on the load port 101 of
the certain processing apparatus 100A, of three certain processing
apparatuses 100A, 100B, and 100C disposed along the section 10c.
Therefore, at this time, the certain processing apparatus 100A is
not in a situation where a FOUP 90 is transportable to its load
port 101. The transport vehicle 20A to which the first transport
command has been allocated and has transported the FOUP 90 to the
standby section 30 waits at the standby point 32a while holding the
FOUP 90 to be transported to the load port 101 of the certain
processing apparatus 100A.
[0049] In such a situation, for example, when some trouble occurs
in the certain processing apparatus 100A, the controller 50, or the
like, the transport vehicle 20A waiting at the standby point 32a
may be unable to transport the FOUP 90 to the load port 101 of the
certain processing apparatus 100A and stay at the standby point
32a.
[0050] In this case, when determining that a first standby
section-withdrawal condition (standby section-withdrawal condition)
is satisfied, the transport controller 50A creates a third
transport command to transport a FOUP 90 to a predetermined
destination. The transport controller 50A then transmits a third
transport command to the transport vehicle controller 50B. The
transport vehicle controller 50B receiving the third transport
command allocates the third transport command to the transport
vehicle 20A. Here, the first standby section-withdrawal condition
is satisfied when a predetermined time or longer has elapsed since
the transport vehicle 20A reaches the standby section 30. Although
here the predetermined destination is the stocker 40, any other
destination may be set.
[0051] Subsequently, as illustrated in FIG. 6, the transport
vehicle 20A transports the FOUP 90 from the standby point 32a to
the stocker 40, and the third transport command is completed. The
first withdrawal control is thus completed.
[0052] Next, the second withdrawal control performed in the
following situation will be described by way of example. As
illustrated in FIG. 7, a FOUP 90 is placed on the load port 101 of
each of three certain processing apparatuses 100A, 100B, and 100C
disposed along the section 10c. Therefore, at this time, the
certain processing apparatuses 100A, 100B, and 100C are not in a
situation where FOUPs 90 are transportable to their load ports 101.
The transport vehicles 20A, 20B, 20C, 20D, 20E that have been
allocated the first transport command and have transported FOUPs 90
to the standby section 30 wait at the standby points 32a, 32b, 32c,
32d, and 31 while holding FOUPs 90 to be transported to the load
port 101 of any of certain processing apparatuses 100A, 100B, and
100C.
[0053] In this situation, for example, when some trouble occurs in
the certain processing apparatuses 100A, 100B, and 100C, the
controller 50, or the like, the transport vehicles 20A, 20B, 20C,
20D, and 20E waiting at the standby points 32a, 32b, 32c, 32d, and
31 may be unable to transport FOUPs 90 to the load ports 101 of the
certain processing apparatuses 100A, 100B, and 100C and stay at the
standby points 32a, 32b, 32c, 32d, and 31. In such a case, a place
for another new transport vehicle 20 to wait is not secured unless
at least one of the transport vehicles 20A, 20B, 20C, 20D, and 20E
waiting in the standby section 30 is withdrawn from the standby
section 30.
[0054] In this case, the transport controller 50A creates a third
transport command when determining that a second standby
section-withdrawal condition (standby section-withdrawal condition)
is satisfied. The transport controller 50A then transmits the third
transport command to the transport vehicle controller 50B. The
transport vehicle controller 50B receiving the third transport
command allocates the third transport command to at least one of
the transport vehicles 20A, 20B, 20C, 20D, and 20E. Here, the
second standby section-withdrawal condition is satisfied when at
least a predetermined number of transport vehicles 20 are waiting
in the standby section 30. Although in this example, the
predetermined number is five, by way of example, any number may be
set.
[0055] Subsequently, at least one of the transport vehicles 20A,
20B, 20C, 20D, and 20E transports the FOUP 90 from the standby
points 32a, 32b, 32c, 32d, and 31 to a predetermined destination,
and the third transport command is completed. The second withdrawal
control is thus completed. Although in this example, the
predetermined destination is the stocker 40, any other destination
may be set.
[0056] The third withdrawal control performed in the following
situation will now be described by way of example. As illustrated
in FIG. 8, a FOUP 90 is placed on the load port 101 of each of
three certain processing apparatuses 100A, 100B, and 100C disposed
along the section 10c. Therefore, at this time, each of the certain
processing apparatuses 100A, 100B, and 100C is not in a situation
where a FOUP 90 is transportable to its load port 101. The
transport vehicles 20A and 20B that have been allocated the first
transport command and have transported FOUPs 90 to the standby
section 30 wait at the standby points 32a and 32b, respectively,
while holding FOUPs 90 to be transported to the load ports 101 of
the certain processing apparatuses 100A and 100B. The transport
vehicle 20C that has been allocated the first transport command and
has transported a FOUP 90 to the standby section 30 waits at the
standby point 32c while holding a FOUP 90 to be transported to the
load port 101 of the certain processing apparatus 100C.
Furthermore, in order to obtain the FOUP 90 placed on the load port
101 of the certain processing apparatus 100C, the transport vehicle
20D is at a position to transfer the FOUP 90 to the load port 101
of the certain processing apparatus 100C.
[0057] In such a situation, the transport vehicle 20D obtains the
FOUP 90 placed on the load port 101 of the certain processing
apparatus 100C. The certain processing apparatus 100C thus enters a
state in which a FOUP 90 is transportable to its load port 101.
[0058] Subsequently, as illustrated in FIG. 9, the transport
controller 50A creates a transport command to withdraw from the
standby section 30. The transport controller 50A then transmits the
transport command to the transport vehicle controller 50B. The
transport vehicle controller 50B receiving the transport command
allocates the transport command to the transport vehicle 20C
waiting in the standby section 30.
[0059] At this time, the transport controller 50A creates a
transport command to withdraw from the standby section 30 and
transport a FOUP 90 to the standby section 30 again. The transport
controller 50A then transmits the transport command to the
transport vehicle controller 50B. The transport vehicle controller
50B receiving the transport command allocates the transport command
to the transport vehicles 20A and 20B downstream from the transport
vehicle 20C (ejection control).
[0060] In the ejection control described in this example, the
second transport command to transport a FOUP 90 to the load port
101 of the certain processing apparatus 100C is allocated, as the
transport command to withdraw from the standby section 30, to the
transport vehicle 20C. In the ejection control, the transport
command to withdraw from the standby section 30 may not be the
second transport command and may be, for example, a transport
command under the first withdrawal control or the second withdrawal
control.
[0061] In the example described here, the transport vehicle
controller 50B allocates a transport command to withdraw from the
standby section 30 to the transport vehicle 20C that is the most
upstream transport vehicle 20 of a plurality of transport vehicles
waiting in the standby section 30. However, the transport vehicle
20 to be allocated the transport command to withdraw from the
standby section 30 may be any other transport vehicle 20, excluding
the most downstream transport vehicle 20, of the transport vehicles
20 waiting in the standby section 30.
[0062] Subsequently, the transport vehicles 20A and 20B that have
withdrawn from the standby section 30 and transported FOUPs 90 to
the standby section 30 again wait in the standby section 30 while
holding FOUPs 90. The transport vehicle controller 50B may
allocate, to the transport vehicles 20A and 20B, again a transport
command to withdraw from the standby section 30 and transport a
FOUP 90 to the standby section 30 again.
[0063] In a situation where such ejection control is performed, for
example, when some trouble occurs in the certain processing
apparatuses 100A, 100B, the controller 50, or the like, the
transport vehicles 20A and 20B waiting at the standby points 32a
and 32b may be unable to transport FOUPs 90 to the load ports 101
of the certain processing apparatuses 100A and 100B and stay at the
standby points 32a and 32b. Based on this, when ejection control is
repeated for the same transport vehicles 20A and 20B a
predetermined number of times or more, for example, some trouble
may occur in the certain processing apparatuses 100A, 100B, the
controller 50, or the like.
[0064] Therefore, the transport controller 50A creates a third
transport command when determining that a third standby
section-withdrawal condition (standby section-withdrawal condition)
is satisfied. The transport controller 50A then transmits the third
transport command to the transport vehicle controller 50B. The
transport vehicle controller 50B receiving the third transport
command allocates the third transport command to the transport
vehicles 20A and 20B waiting at the standby points 32a and 32b.
Here, the third standby section-withdrawal condition is satisfied
when the transport vehicle 20 that has been allocated the first
transport command has withdrawn from the standby section 30 a
predetermined number of times or more.
[0065] Subsequently, the transport vehicles 20A and 20B transport
FOUPs 90 from the standby points 32a and 32b to the stocker 40, and
the third transport command is completed. The third withdrawal
control is thus completed. Although here the predetermined
destination is the stocker 40, any other destination may be
set.
[0066] As described above, in the transport system 1 and the
transport method performed in the transport system 1, even if a
FOUP 90 is not transportable to the load ports 101 of the certain
processing apparatuses 100A, 100B, and 100C, the transport vehicle
20 picks up a FOUP 90 and starts traveling toward the standby
section 30. When the situation changes so that a FOUP 90 is
transportable to the load ports 101 of certain processing
apparatuses 100A, 100B, and 100C, the transport vehicle 20B
travelling toward the standby section 30 or the transport vehicle
20B having reached the standby section 30 and waiting while holding
a FOUP 90 is able to immediately transport the FOUP 90 to the load
ports 101 of the certain processing apparatuses 100A, 100B, and
100C without the need for performing an operation, such as
picking-up, again. This structure and operation decrease or prevent
reduction in the operating rate of the certain processing
apparatuses 100A, 100B, and 100C.
[0067] In the transport system 1, for example, even if FOUPs 90 are
placed on the load ports 101 of the certain processing apparatuses
100A, 100B, and 100C in the subsequent process and thus another
FOUP 90 is unable to be transported to the load ports 101 of the
certain processing apparatuses 100A, 100B, and 100C, the transport
vehicle 20 is able to transport another FOUP 90, for example, from
the load port of the processing apparatus 100 in the previous
process to the standby section 30. This structure and operation
reduce the time required to pick up a FOUP 90 from the load port
101 of the processing apparatus 100 in the previous process. This
decreases or prevents reduction in the operating rate of the
processing apparatus 100 in the previous step.
[0068] In the transport system 1, when determining that the standby
section-withdrawal condition is satisfied, the transport vehicle
controller 50B allocates the third transport command to transport a
FOUP 90 to the stocker 40 to the transport vehicle 20 that has been
allocated the first transport command. This structure and operation
prevent, for example, the transport vehicle from staying in the
standby section 30 due to some trouble occurring in the certain
processing apparatuses 100A, 100B, and 100C.
[0069] In the transport system 1, when the transport vehicle
controller 50B determines, as the first standby section-withdrawal
condition, that a predetermined time or longer has elapsed since
the transport vehicle 20 that has been allocated the first
transport command reaches the standby section 30, the transport
vehicle controller 50B allocates the third transport command to the
transport vehicle 20. This prevents, for example, the transport
vehicle 20 from staying in the standby section 30 due to some
trouble occurring in the certain processing apparatuses 100A, 100B,
and 100C.
[0070] In the transport system 1, when the transport vehicle
controller 50B determines, as the second standby section-withdrawal
condition, that a predetermined number or more transport vehicles
20 wait in the standby section 30, the transport vehicle controller
50B allocates the third transport command to at least one of the
transport vehicles 20. This prevents, for example, the transport
vehicle 20 from staying in the standby section 30 due to some
trouble occurring in the certain processing apparatuses 100A, 100B,
and 100C.
[0071] In the transport system 1, the transport vehicle 20 travels
along the track 10 in one direction. When a plurality of transport
vehicles 20 are waiting in the standby section 30, and a transport
command to withdraw from the standby section 30 is allocated to one
of the transport vehicles 20, excluding the most downstream
transport vehicle 20, of the transport vehicles 20, the transport
vehicle controller 50B allocates, to another transport vehicle 20
downstream from the transport vehicle 20, a transport command to
withdraw from the standby section 30 and transport a FOUP 90 to the
standby section 30. When the transport vehicle controller 50B
determines, as the third standby section-withdrawal condition, that
the transport vehicle 20 that has been allocated the first
transport command withdraws from the standby section 30 a
predetermined number of times or more, the transport vehicle
controller 50B allocates the third transport command to the
transport vehicle 20. This prevents, for example, ejection control
from being repeated due to some trouble occurring in the certain
processing apparatuses 100A, 100B, and 100C.
[0072] Although preferred embodiments of the present invention have
been described above, the present invention is not limited to the
foregoing preferred embodiments. For example, in the foregoing
preferred embodiments, the transport vehicle 20 preferably travels
along the track 10 in one direction. However, the transport vehicle
20 may travel along the track 10 bidirectionally.
[0073] In the foregoing preferred embodiments, the transport system
1 preferably includes three certain processing apparatuses 100A,
100B, and 100C in the section 10c. However, the transport system 1
may include more than three certain processing apparatuses or may
include less than three (one or two) certain processing apparatuses
in the section 10c.
[0074] As illustrated in FIG. 10, the transport vehicle 20 may
travel along the track 10 in one direction. The standby section 30
may be connected in parallel with a second travel section 33B
continuous to the upstream side of a first travel section 33A
including the position to transfer a FOUP 90 to the load port 101
of each of the certain processing apparatuses 100A, 100B, and 100C.
In particular, one first travel section 33A may be provided for the
certain processing apparatuses 100A, 100B, and 100C.
[0075] In this case, compared with the foregoing preferred
embodiments, a section 10f is connected in parallel with the
section 10b. That is, the section 10b corresponds to the second
travel section 33B, and the section 10f corresponds to the standby
section 30. Specifically, the section 10f includes an upstream side
branching from the upstream side of the second travel section 33B
(section 10b) and includes a downstream side merging with the
downstream side of the second travel section 33B (section 10b),
that is, the upstream side of the first travel section 33A (section
10c).
[0076] In such a track 10, the transport vehicle 20 entering
through the upstream side of the section 10a travels from the
section 10a to the section 10b and then travels to the section 10c.
Alternatively, the transport vehicle 20 entering through the
upstream side of the section 10a travels from the section 10a to
the section 10f and then travels to the section 10c. The transport
vehicle 20 traveling to the section 10c travels to the section 10d
and then exits to the downstream side. Alternatively, the transport
vehicle 20 traveling to the section 10c travels from the section
10c to the section 10e and travels again to the section 10b. The
configuration of the track 10 in the figure is illustrated only by
way of example and is not limitative.
[0077] In such a transport system 1, the transport vehicle 20
travels along the track 10 in one direction. The standby section is
connected in parallel with the second travel section 33B continuous
to the upstream side of the first travel section 33A including the
position to transfer a FOUP 90 to the load port 101 of each of the
certain processing apparatuses 100A, 100B, and 100C. This enables
the transport vehicle 20 to wait in the standby section 30 without
interrupting travel of the transport vehicle 20 from the second
travel section 33B to the first travel section 33A.
[0078] In such a transport system 1, one first travel section 33A
is provided for the certain processing apparatuses 100A, 100B, and
100C. In this configuration, since one standby section 30 is
associated with the certain processing apparatuses 100A, 100B, and
100C, the area of the space necessary to provide the standby
section 30 is able to be reduced.
[0079] In such a transport system 1, three certain processing
apparatuses 100A, 100B, and 100C are provided in the first travel
section 33A including the position to transfer a FOUP 90 to the
load port 101 of each certain processing apparatus. However, the
transport system 1 may include more than three certain processing
apparatuses or may include less than three (one or two) certain
processing apparatuses in the first travel section 33A.
[0080] In the foregoing preferred embodiments, the transport
vehicle controller 50B may be configured or programmed to perform
all or a portion of the functions of the transport controller 50A,
or the transport controller 50A may be configured or programmed to
perform all or a portion of the functions of the transport vehicle
controller 50B. Alternatively, one controller 50 may be configured
or programmed to perform the functions of the transport controller
50A and the transport vehicle controller 50B.
[0081] In the foregoing preferred embodiments, the object
transported by the transport system 1 of the present invention is
not limited to a FOUP 90 accommodating a plurality of semiconductor
wafers and may be any other container accommodating glass wafers,
reticles, and others. The transport systems according to preferred
embodiments of the present invention are applicable to not only a
semiconductor fabrication plant but also any other facilities.
[0082] In the foregoing preferred embodiments, an OHT has been
illustrated as the transport vehicle 20. However, the transport
vehicle 20 may not be an OHT and may be any device that can travel
along the track 10 and transport an object to the load port 101 of
the processing apparatus 100.
[0083] While preferred embodiments of the present invention have
been described above, it is to be understood that variations and
modifications will be apparent to those skilled in the art without
departing from the scope and spirit of the present invention. The
scope of the present invention, therefore, is to be determined
solely by the following claims.
* * * * *